Planned Inspection of Dungeness B

Site: Dungeness B

IR number: 15-063

Date: August 2015

LC numbers: 2, 7 , 26

Executive summary

Purpose of intervention

This was a planned inspection at EDF Energy Nuclear Generation Ltd’s (NGL’s) Dungeness B (DNB) power station, undertaken as part of the planned Integrated Intervention Strategy (IIS) for the Civil Nuclear Reactor Programme (CNRP) of the Office for Nuclear Regulation (ONR).

Interventions Carried Out by ONR

The key interventions during this inspection were for licence compliance covering the following licence conditions (LC):

Licence Condition 2 – Marking of the site boundary

Licence Condition 7 – Incidents on the site

Licence Condition 26 – Control and supervision of operations

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable

Key Findings, Inspector's Opinions and Reasons for Judgements Made

For LC 2, I started to inspect the licensee’s arrangements and their implementation, but was unable to complete the inspection due to the effects of heavy rainfall on the site, described below. Whilst a number of areas for improvement were found, none required immediate action and the inspection will be completed at a later date. I could not rate the licensee’s compliance as the inspection was not completed.

For LC 7, I inspected the licensee’s processing of incident reports for two sample dates, placing of actions as a result of the reports, including investigations, and witnessed a daily meeting that screens incident reports. I judged these were all adequate and hence assigned an IIS rating of 3.

For LC 26, I inspected the use of quality plans and operating instructions to control the return to service of Reactor 22 from its statutory outage. I found that the quality plans were generally adequate with some scope for minor improvements. I also found that the instructions used in the Central Control Room were adequate, although I found some deficiencies in the control and supervision of their use and agreed actions with the station to improve this. I concluded that the control and supervision of operations was below standard and have therefore assigned an IIS rating of 4.

The site experienced heavy rainfall on 13 August 2015, during the inspection, which resulted in water ingress into a number of buildings and areas within them. This impacted on the operability of the fire alarm system and potentially other plant and the need to muster the whole site in difficult conditions. The reasons for the widespread impact on the site need to be investigated when further information is available. I witnessed the site’s emergency organisation dealing with aspects of the incident, primarily in managing personnel on the site. I judged that the site’s emergency organisation could have been more effective and will follow this up during a future inspection.

In relation to the other activities undertaken in this intervention, no key findings arose.

The intervention was performed in line with ONR’s guidance requirements (as described in our technical inspection guides) in the areas inspected.

Conclusion of Intervention

From the evidence obtained during this intervention, no matters have been identified that are likely to have a significant impact on nuclear safety on the station at this time. Therefore, no additional regulatory action arising from this visit is considered necessary at this time.